《道德形而上学基础·序言》第1节
Ancient Greek philosophy was divided into three sciences: physics, ethics, and logic. This division is perfectly suitable to the nature of the thing; and the only improvement that can be made in it is to add the principle on which it is based, so that we may both satisfy ourselves of its completeness, and also be able to determine correctly the necessary subdivisions. All rational knowledge is either material or formal: the former considers some object, the latter is concerned only with the form of the understanding and of the reason itself, and with the universal laws of thought in general without distinction of its objects. Formal philosophy is called logic. Material philosophy, however, which has to do with determinate objects and the laws to which they are subject, is again twofold; for these laws are either laws of nature or of freedom. The science of the former is physics, that of the latter, ethics; they are also called natural philosophy and moral philosophy respectively. Logic cannot have any empirical part; that is, a part in which the universal and necessary laws of thought should rest on grounds taken from experience; otherwise it would not be logic, i.e., a canon for the understanding or the reason, valid for all thought, and capable of demonstration. Natural and moral philosophy, on the contrary, can each have their empirical part, since the former has to determine the laws of nature as an object of experience; the latter the laws of the human will, so far as it is affected by nature: the former, however, being laws according to which everything does happen; the latter, laws according to which everything ought to happen. Ethics, however, must also consider the conditions under which what ought to happen frequently does not. We may call all philosophy empirical, so far as it is based on grounds of experience: on the other hand, that which delivers its doctrines from a priori principles alone we may call pure philosophy. When the latter is merely formal it is logic; if it is restricted to definite objects of the understanding it is metaphysic.
注释摘要
康德在序言的开篇就借用古希腊哲学的三分法来建立自己的论证框架，这个借用本身就很能说明问题。他说古代哲学分为物理学、伦理学和逻辑学，并认为这个划分从根本上契合事情的本来面目。但他紧接着就提出，这里唯一的改进就是补充这个划分所依据的原则。这可不是一句无关紧要的补充，因为康德看事情永远是从原则出发的：不是先有了学科再去找原则，而是必须先有原则，人们才能确定这个划…